[tuxracer]

If you migrate to HTTP2 or move to a host that already supports it then cutting down on "round trips" is an obsolete concern altogether.

[jacquesm]

HTTP2 does not magically bundle all connections to one. It still very much depends on how you build up your page.

[floatboth]

It does not magically split one connections into many. One domain == one connection. Sure it won't undo your "domain sharding" hacks and merge your CDNs, yeah :)